[GIF] Source (Expanding diamonds)

Mathematically very simple, though as the title of the still alludes to, I like to think of these as the concentric spheres in the
$\ell^1$ norm. The basic form is actually inspired by a stained glass piece my grandfather made several decades ago that I use as a Christmas decoration.

The code is kind of ugly, especially since I'm just covering up the diamonds that get too big: